Rapid case ascertainment (case identification within two months after diagnosis) is critical to the successful conduct of quality, population-based, epidemiologic studies, particularly case-control studies that incorporate molecular biology and biomarkers. The goal of the Rapid Case Ascertainment (RCA) Core, under the direction of Dr. Andrew Olshan, is to support population-based epidemiology research by providing personnel for the rapid ascertainment of cancer cases in North Carolina. The RCA Core works with the NC Central Cancer Registry and investigators to facilitate case identification and data collection including traveling to and working with smaller, undermanned hospitals, located primarily in rural central and eastern North Carolina counties. The RCA Core also provides consultation and administrative assistance to researchers through the coordination of project IRB approvals and HIPAA compliance at participating hospitals; reports to hospitals and tumor registrars; database development; and activities among project investigators, the NC Central Cancer Registry, and related state committees. This Core Facility makes possible continued quality, cost-effective population-based research in diverse communities. The four current circuit-riding data coordination positions have helped reduce the workload from ongoing studies by providing centralized coordination ascertainment, especially for hospitals in rural and underserved counties. Case-finding takes place for multiple studies during a single trip, providing a high degree of efficiency and cost effectiveness for the studies. In 2003, six peer-reviewed members from two programs used the Core to identify 9,256 new cases new cases of breast, colorectal, prostate, head and neck, and ovarian cancer cases in selected counties for eight studies. UNC Lineberger investigators continue to expand their efforts in population-based studies that rely on rapid case ascertainment. Future plans include the development of a secure website dedicated to RCA in North Carolina. This will be a useful tool to provide valuable information to hospital cancer registrars and investigators for ongoing and upcoming research.